200x 1mm oversize valves, worth the money?

[hawaiirider]

hi i have a modded x (cam. hi comp, 28mm carb, exhaust) i was considering the 1mm oversize valve (intake) but my valves are fairly new and i dont know how much performance or where in the range the power will be affected by this was hoping for some opinions.
thank you

[Dave8338]

Hard to say...
The stock head will need to be ported for the new seats. Pockets smoothed out, etc.

It is without doubt, that the stock valves/heads are the bottleneck in the equation. I think it all boils down to how much does one want to spend, chasing a few extra ponies. :beer

[hawaiirider]

its been flowported already, a few ponies is ALOT on a motor that only puts out mid teens on the dyno!

[El Camexican]

If you don't open the seat to match the larger valve it's not worth it, but you need to be sure the seat has enough material to allow it. In saying that 1mm mm isn't much, shouldn't be a concern for you. If you have the larger cam and carb already it would pick you up a bit, but a larger exhaust valve to make a matching set is what would really make a difference.

[Dave8338]

If you don't open the seat to match the larger valve it's not worth it, but you need to be sure the seat has enough material to allow it. In saying that 1mm mm isn't much, shouldn't be a concern for you. If you have the larger cam and carb already it would pick you up a bit, but a larger exhaust valve to make a matching set is what would really make a difference.

Yeppers ! ! Too bad that without a complete weld shut, milling, and new valve angle, it is all but impossible on these little monsters.

Someday, in all my boredom, I would like to attempt a 4-valve head setup. It is possible but the machining and cam production would cost a fortune. :naughty:

[atc007]

Unless you are running this thing a couple hours a year,or less. Save the aggravation. Be happy with what you have lol.. You will get into reliability problems stretching that little girl much further...Top or bottom. Seen it a lot of times.

[Dave8338]

its been flowported already, a few ponies is ALOT on a motor that only puts out mid teens on the dyno!

I agree ! ! ! :twisted:


Unless you are running this thing a couple hours a year,or less. Save the aggravation. Be happy with what you have lol.. You will get into reliability problems stretching that little girl much further...Top or bottom. Seen it a lot of times.

Very true. Somewhere in the middle headed for the top, is always comfy... :cool:

[Dirtcrasher]

Now that I saw thew 30 degree cut 200X valves Mickey Dunlap showed us, I think that might be a good option......

[Dave8338]

Now that I saw thew 30 degree cut 200X valves Mickey Dunlap showed us, I think that might be a good option......

Certainly has to be cheaper. Have a link? I must have missed that. :wondering

[NeverLift]

Post #33 has the picture of the valves he's talking about.

http://www.3wheelerworld.com/showthread.php/172242-200x-83-85-head-flow-numbers

[YTZ drew]

Someday, in all my boredom, I would like to attempt a 4-valve head setup. It is possible but the machining and cam production would cost a fortune. :naughty:
It has been done using a VT250 cylinder head. See the article below, lots of good info in it, so I saved it to my pc.
http://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&ved=0CCAQFjAA&url=http%3A%2F%2Fwww.xrv.org.uk%2Fforums%2Fattachm ents%2Fother-honda%2F17679d1333956643-xlr-125r-1999-xl185-cylinder-honda-xr200-mods.pdf&ei=8fflVP_oIY-lyAT_u4GwAQ&usg=AFQjCNGl2YYTYBK_N9bqzwVuEucDxo5eug&bvm=bv.85970519,d.aWw&cad=rja

[hawaiirider]

anyone know the cost for the work to get one of these in?
http://www.fourstroketech.net/#!__products/honda/vstc1=atc-83'-85'-200x
http://www.webcamshafts.com/index_blank.html?pages/vehicle_search.html

[Mickey Dunlap]

The first thing you need to know, is how much does it flow now. You said it was flow ported already but what are the numbers. I can tell you if you send the head in, but any other opinions other then that doesn't tell you much, you are just confusing your self.

[hawaiirider]

i have no idea mickey, how much do you charge to set me up with the larger valve if i send it in? i know youll have to re flow port it.

[Mickey Dunlap]

i have no idea mickey, how much do you charge to set me up with the larger valve if i send it in? i know youll have to re flow port it.

I don't charge anything to check the flow, but if I install the big valve and valve you are looking at $50. First check the flow and go from there.

[Dirtcrasher]

It has been done using a VT250 cylinder head. See the article below, lots of good info in it, so I saved it to my pc.
http://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&ved=0CCAQFjAA&url=http%3A%2F%2Fwww.xrv.org.uk%2Fforums%2Fattachm ents%2Fother-honda%2F17679d1333956643-xlr-125r-1999-xl185-cylinder-honda-xr200-mods.pdf&ei=8fflVP_oIY-lyAT_u4GwAQ&usg=AFQjCNGl2YYTYBK_N9bqzwVuEucDxo5eug&bvm=bv.85970519,d.aWw&cad=rja


THANK YOU!!

Amazing article......

[greenhuman]

Fit a CRF230F head. 2mm bigger valves std.

[B S]

Looks like fun

[Mickey Dunlap]

Fit a CRF230F head. 2mm bigger valves std.

I ordered in one of those to see how it flows. The big factor on the valve I use is the back side of the valve. Honda doesn't have the back side that allows good flow in the mid lifts and cutting a 30* angle on the back side doesn't work as good either.